[PATCH] Fix stack memory protection on targets where the stack grows upward

[Florian Weimer]

* John David Anglin:

> On 2017-04-16, at 5:27 PM, Florian Weimer wrote:
>
>> This is essentially HPPA-specific code, right?  So I guess we can do
>> whatever it takes there.
>
> I believe the metag architecture also has a stack that grows up.

I'm sure there are others, but HPPA is the only one with a glibc port.